Spectrally sensitized silver halide photographic emulsion

ABSTRACT

A spectrally sensitized silver halide photographic emulsion containing at least one sensitizing dye represented by the following general formula   WHEREIN Z and Z&#39;&#39;, each represents the atomic group necessary to complete a benzothiazole nucleus, a benzoselenazole nucleus or a naphthothiazole nucleus, R and R&#39;&#39; each represents an alkyl group, a carboxyalkyl group or a sulfoalkyl group, at least one of said R and R&#39;&#39; being a carboxyalkyl or a sulfoalkyl group, X represents an anion and n is 0 or 1, is disclosed. The emulsion is highly sensitive to red light.

United States Patent 1 Sato et al.

[ 1 *Dec. 4, 1973 SPECTRALLY SENSITIZED SILVER HALIDE PHOTOGRAPHIC EMULSION [75] Inventors: Akira Sato; Tadashi lkeda;

Yoshiyuki Nakazawa; Yashuharu Nakamura; Haruo Takei, all of Kanagawa, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan 21 Appl. No.: 115,550

[30] ForeignApplication Priority Data I Feb. 16, 1970 Japan 45/13284 [52] US. Cl 96/137, 96/139, 260/240.6

[5 1 Int. Cl [58] Field of Search, 96/137, 142, 139

[56] References Cited UNITED STATES PATENTS 1,846,303 2/1932 Brookern 96/137 2,126,078 8/1938 Zeh et al 96/137 2,233,511 3/1941 Brooker et 96/137 3,677,765 7/1972 Nadazawa 96/137 OTHER PUBLlCATlONS Brooker et al., Journal American Chemical Society, Vol. 57, pages 2,480-2,488, (1935).

Primary Examiner-4. Travis Brown Attorney-Sughrue, Rothwell, Mion, Zinn and Macpeak [57 ABSTRACT v A spectrally sensitized silver halide photographic emulsion containing at least one sensitizing dye represented by the following general formula wherein Z and Z, each represents the atomic group necessary to complete a benzothiazole nucleus, a benzoselenazole nucleus ora naphthothiazole nucleus, R and R each represents an alkyl group, a carboxyalkyl group or a sulfoalkyl group, at least one of said R and R being a carboxyalkyl or a sulfoalkyl group, X represents an anion and n is 0 or 1, is disclosed. The emulsion is highly sensitive to red light.

5 Claims, 1 Drawing Figure PMENIEIHIH: 419m 3.775.739

INVENTORS AKIRA SATO TADASHI IKEDA YOSHIYUKI NAKAZAWA YASHUHARU NAKAMURA HARUO TAKE] BY Swahili; KM Ml \u 4 AM V K ATTORNEYS 1 SPECTRALLY SENSITIZED SILVER IIALIDE PHOTOGRAPIIIC EMULSION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a silver halide photographic emulsion containing a novel sensitizing dye. More particularly, the present invention relates to a silver halide photographic emulsion having a high sensitivity to red.

2. Description of the Prior Art It is well known in the technical field of silver halide manufacture, emulsion manufacutre, that addition of a sensitizing dye to a silver halide photographic emulsion broadens the wave length region over which the emulsion is sensitized, thereby optically sensitizing the silver halide photographic emulsion. It is generally accepted that the spectral sensitivity is most often influenced by the chemical structure of the sensitizing dye, and particularly the maximum spectral sensitivity in the longer wave length region. This is presumed to be caused by sensitizing dye aggregation on the surface of silver halide grains, is apt-to be influenced by the chemical structure or steric effects of substituents of the sensitizing dye. Accordingly, if a desired photosensitive wave length region is to be highly sensitized with a photographic light sensitive material, it is practically extremely important to employ such a sensitizing dye as having the desired selectivity. I

SUMMARY OF THE INVENTION The present invention provides-a silver halide photographic emulsion which is highly sensitive to red. The present invention can be achievedby incorporating a novel sensitizing dye into a silver halide photographic emulsion. The novel sensitizing dye is represented by the following general formula (I):

wherein Z and Z represent the atomic groups neces sary to complete a benzothiazole nucleus (for example, the nucleus of benz'othiazole, 5-chlorobenzothiazole, 5-bromobenzothiazole, 5-methylbenzothiazole, 5,6-dimethylbenzothiazole, S-phenylbenzothiazole, 5- methoxybenzothiazole, S-ethoxybenzothiazole, 5- methoxycarbonylbenzothiazole, 5- hydroxybenzothiazole, 5-methyl-6-ethoxybenzothiazole, and the like), a benzoselenazole nucleus (for example, the nucleus of benzoselenazole, 5- chlorobenzoselenazole, 5-methylbenzoselenazole, 5- methoxybenzoselenazole, S-hydroxybenzoselenazole, 5-methoxycarbonylbenzoselenazole, and the like) or a naphthothiazole nucleus (for example, the nucleus of B -naphthothiazole); wherein R and R each represents an alkyl group (for example, an ethyl group, an npropyl group, and the like), a carboxyalkyl group (for example, a B -carboxyethyl group, a v -carboxypropyl group, a 6 -carboxybutyl group, a w -carboxypentyl group, and the like), or a sulfoalkyl group, (for example, a v -sulfopropyl group, a v -sulfobutyl group, a 8 -sulfobutyl group, and the like), at least one of R and R being a carboxyalkyl or sulfoalkyl group; wherein X represents an anion (for example, a chloride ion, a bromide ion, an iodide ion, a p-toluene sulfonate ion, an ethyl sulfonate ion and the like); and wherein n is 0 or 1 provided that when n is 0, the dye is an intramolecular salt.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing is a graphical representation of the spectral sensitization of a photographic emulsion incorporating a novel sensitizing dye of the present invention, Dye No. 11 described hereinafter and in the Examples, in comparison with a photographic emulsion incorporating a sensitizing dye, Dye B, described hereinafter and in the Examples but outside the scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Dye #2:

The novel sensitizing dyes of the general formula (i) employed in accordance with the present invention can be prepared in a conventional manner. For example, they maybe readily synthesized by one skilled in the art in the manner described in US. Pat. No. 2,503,776, in German Patent No. 929,080, or in German Patent No. l,072,765.

Thus, the novel sensitizing dyes represented by the general formula (l) can be prepared by reacting a compound represented by the following general formula I CH:

R ')n (II) wherein Z, R, X and n have the same meaning asae fined in the above-described general formula (I), and R" represents an alkyl group, such as a methyl and an ethyl group, with a compound repre'sented by thefollowing general formula (III):

wherein Z, R, X and rill ave thesa rriemeaning astrafined in the above-described general formula (I). The reaction can be effected by heating the reactants-under reflux in a suitable solvent, such as methanol, ethanol and isopropanol, in the presence of a basic condensing agent, such as triethylamine.

The physical properties of the typical examples ofthe novel sensitizing dyes of the general formula (I) presented hereinbefore are shown in Table 1 below.

The sensitizing dyes employed according to the present invention are capable of spectrally sensitizing a silver halide photographic emulsion. They are particularly effective in broadening the spectrally sensitizable region of a gelatino-silver halide photographic em'ulsion. They are also capable of sufficiently sensitizing a photographic emulsion containing a hydrophilic colloid other than gelatin, for example, agar collodion, watersoluble cellulose derivatives, polyvinyl alcohol and other synthetic or natural hydrophilic resins. They are further effective as sensitizing dyes for use in electrophotographs prepared by the zinc oxide method.

In the emulsion employed in accordance with the present invention, various kinds of the silver salts, for example, silver bromide and mixed silver halides, such as silver iodobromide, silver chlorobromide and silver chloroiodobromide, can be used.

In order to prepare the sensitized photographic emulsion of the present invention, one or more than one of the sensitizing dyes have only to be incorporated into a photographic emulsion in any conventional manner. In practice, usually the dyes are dissolved in a suitable solvent, such as methanol and ethanol, and the resulting solution is added into the photographic emulsion. The amount of the sensitizing dye incorporated into the emulsion can be varied over a wide range gf flrorr 5 to 200 mg/kg of theemulsion containing 0.5 mole of silver halide, depending upon the effect desired.

Furthermore, it is possible to apply hyper-sensitization or super-sensitization to the photographic emulsion of the present invention in a conventional manner, as described in, eg, C.E. Mees and TH. James, The Theory of the Photographic Process, Third Edition, p. 252, 253-256, The MacMillan Company.

On manufacturing the photographic emulsion in accordance with the present invention, it is also possible to incorporate into the emulsion, in a conventional manner, generally used additives, such as sensitizers, stabilizers, toning agents, film hardening agents, surface active agents, antifogging agents, plasticizers,

development-acceleraters, color-developing agents,

and fluorescent whitening agents. v

The photographic emulsion according to the present inventionmay be coated in a conventional manner on a suitable support, suchasa glass sheet, a cellulose derivative film, a synthetic resin film, and a 'baryta-coated paper. I

The present invention will be'further explained in greater detail by reference to thefollowing examples. It is to be understood, however, that the specific examples given herein are only illustrative and the present invention is not intended to be limited thereby.

. EXAMPLES The sensitizing dyes of the invention exemplified above were added into gelatino-silver iodobromide emulsions (Agl AgBn= 7 moles 93 moles) to prepare the corresponding silver halide photographic emulsions. The emulsions were then coated 011 bases of cellulose triacetate followed by drying, the thus coated emulsion thereafter being exposed to light through Fuji No. 7 filter, a red filter manufactured by Fuji Photo Film Co., Ltd. and capable of passing therethrough only light having a wave length longer than 580 nm) followed by development wherein, as a developer there was employed a liquid having the composition as shown in the following Table 2.

TABLE 2 Metal 8 Sodium Sulfite I00 g Hydroquinone 5 g Borax 2g Water added to make the total volume to 1 liter.

In the following Table 3, the sensitivity to red and the maximum sensitization wave length results with the sensitizing dyes of the invention exemplified hereinbe- TABLE 3 Amount of the Wavelength Rela- Dye Added where maxitive mum sensitisensi- Ex. Dye (IO mol/kg Emulzation obtivity No. No. emulsion) sion tained (nm) to red I l 8 AgBr/l 638 900 2 2 8 do 634 820 3 3 8 do 626 920 4 4 8 do 640 900 5 5 8 do 628 850 6 6 8 do 625-630 800 7 7 8 do 632-634 850 8 8 8 do 650 700 9 9 8 do 645 900 l l0 8 do 620 810 I l l l 6 do 644 I750 l2 l2 8 do 635 800 l3 l3 8 do 634 850 l4 l4 8 do 620-625 700 l l5 8 do 638 650 Comparativc Test Nos. 1' A 8 AgBr/l 660 540 2' B 10 do 620 I00 3 C 8 do 628 580 For comparison purposes The sensitizing dyes used for comparison have the following formulas:

Comparative Sensitizing Dye (A):

Comparative Sensitizing Dye (B):

S l S gHs I (B Comparative Sensitizing Dye (O):

The sensitivity to red was expressed as relative sensitivity to red with respect to that estimated as 100 for Sensitizing Dye B which was obtained by its exposure to light using Fuji 4 filter (red filter).

From the above data, it can be seen that the silver halide photographic emulsion of the present invention provides superior photographic properties. e.g., higher red sensitivity, to the silver halide photographic emulsion containing a sensitizing dye outside the scope of the present invention.

What is claimed is:

1. A silver halide photographic emulsion containing at least one sensitizing dye represented by the following general formula wherein Z and Z each represent the atomic group necessary to complete a nucleus selected from the group consisting of a benzothiazole nucleus, a benzoselenazole nucleus, and a naphthothiazole nucleus; wherein R and R each is selected from the group consisting of an alkyl group, a carboxyalkyl group, and a sulfoalkyl group; wherein at least one of R and R is selected from the group consisting of a carboxyalkyl group and a sulfoalkyl group; wherein X is an anion; and wherein n is 0 or 1.

2. A silver halide photographic emulsion as claimed in claim 1, wherein Z and Z are selected from the atom iggroups necessary to complete a benzothiazole, aTchlormhiazole; a 5 brornober'ilioth i azole, a

5-methylbenzothiazole, a 5, 6-dimethylbenzothiazole,

Dye #141 4. A silver halide photographic emulsion as claimed in claim 1, wherein the amount of the sensitizing dye ranges from to 200 mg of dye per kg of emulsion containing 0.5 mole of silver halide.

S s 5 5. A photographic light-sensitive material comprising H: a support having thereon at least one layer containing A; the silver halide emulsion as claimed in claim 1. C gl/ N OH $211, nm or Dyo #15: v V

zHa 0x803- 

2. A silver halide photographic emulsion as claimed in claim 1, wherein Z and Z'' are selected from the atomic groups necessary to complete a benzothiazole, a 5-chlorobenzothiazole, a 5-bromobenzothiazole, a 5-methylbenzothiazole, a 5,6-dimethylbenzothiazole, a 5-phenylbenzothiazole, a 5-methoxybenzothiazole, a 5-ethoxybenzothiazole, a 5-methoxycarbonylbenzothiazole, a 5-hydroxybenzothiazole, a 5-methyl-6-ethoxybenzothiazole, a benzoselenazole, a 5-chlorobenzoselenazole, a 5-methylbenzoselenazole, a 5-methoxybenzoselenazole, a 5-hydroxybenzoselenazole, a 5-methoxycarbonylbenzoselenazole, and a Beta -naphthothiazole nucleus; and wherein R and R'' are selected from the group consisting of an ethyl, an n-propyl, a Beta -carboxyethyl, a Nu -carboxypropyl, a delta -carboxybutyl, a omega -carboxypentyl, a Nu -sulfopropyl, a Nu -sulfobutyl, and a delta -sulfobutyl group.
 3. A silver halide photographic emulsion as claimed in claim 1, wherein said sensitizing dye is selected from the group consisting of
 4. A silver halide photographic emulsion as claimed in claim 1, wherein the amount of the sensitizing dye ranges from 5 to 200 mg of dye per kg of emulsion containing 0.5 mole of silver halide.
 5. A photographic light-sensitive material comprising a support having thereon at least one layer containing the silver halide emulsion as claimed in claim
 1. 